Body-worn cameras do not have clear or consistent effects on most officer or citizen behaviors, but different practices need further evaluation
Law enforcement agencies have rapidly adopted body-worn cameras (BWCs) in the last decade with the hope that they might improve police conduct, accountability, and transparency, especially regarding use of force.
Overall, there remains substantial uncertainty about whether BWCs can reduce officer use of force, but the variation in results over studies suggests there may be conditions in which BWC could be effective. BWCs also do not seem to affect other police and citizen behaviors in a consistent manner, including officers’ self-initiated activities or arrest behaviors, dispatched calls for service, or assaults and resistance against police officers. BWCs can reduce the number of citizen complaints against police officers, but it is unclear whether this finding signals an improvement in the quality of police-citizen interactions or a change in reporting.
Research has not directly addressed whether BWCs can strengthen police accountability systems or police-citizen relationships.
What is this review about?
The last decade has been marked by the rapid adoption of BWCs by the police and a growing body of evaluation research on the technology’s effects. Spurred on by high-profile officer-involved shooting incidents and protests, many citizens and community groups have supported the adoption of BWCs, hoping that this technology will deter police misconduct, better capture use-of-force events, and increase police accountability and transparency.
At the same time, some police officers and community members have expressed concerns that BWCs might discourage citizens from reporting crimes or cause officers to pull back on preventative or proactive activities that may help prevent offending. This Campbell systematic review synthesizes research on the impacts of BWCs on officer and citizen behaviors.
What is the aim of this review?
This Campbell systematic review summarizes the evidence from 30 studies of the effects of body-worn cameras on several officer and citizen behaviors. The majority of studies are from the USA.
What studies are included?
Studies eligible for this review included those that examined the use of BWCs by law enforcement officers using either randomized controlled trials or quasi-experimental research designs, and that measured police or citizen behaviors, rather than their perceptions. All studies compared officers wearing BWCs with officers not wearing BWCs.
Thirty eligible studies were found, which reported on 12 different types of outcome measures of officer or citizen behavior. A total of 116 effects on these outcomes were examined. Almost all studies were carried out in a single municipal jurisdiction (e.g., a city or county). Not all studies are clear where they were conducted, but the majority are from the USA.
What are the findings of this review?
Overall, the way BWCs are currently being used may not substantially affect most officer or citizen behaviors. The use of BWCs does not have consistent or significant effects on officers’ use of force, arrest activities, proactive or self-initiated activities, or other measured behaviors. Nor do BWCs have clear effects on citizens’ calls to police or assaults or resistance against officers.
Analysis suggests restricting officer discretion in turning on and off BWCs may reduce police use of force, but more assessment is needed.
BWCs may reduce the number of citizen complaints against police officers, although it is unclear why complaints decline.
What do the findings of the review mean?
BWCs are one of the most rapidly diffusing and costly technologies used by police agencies today. This review questions whether BWCs bring the expected benefits to the police and their communities.
Existing research does not evaluate whether police accountability or police-citizen relationships are strengthened by BWCs. Much more knowledge is needed about when BWCs do create desired effects, and whether they are cost-effective.
For the many police agencies that have already purchased BWCs, researchers should continue testing for ways in which both police and citizens might gain benefits from the cameras’ continued use. These could include limiting the discretion that officers have with BWC use, using BWCs for coaching, training or evidentiary purposes, and finding ways that BWCs can be used to strengthen police-citizen relationships, internal investigations, or accountability systems.
How up-to-date is this review?
This review includes studies completed and available in written form as of September 2019.